The following objectives are to be accomplished in order to isolate, characterize, and study the ttansport systems form normal and neoplastic cells: Preparation of purified plasma membranes from normal and neoplastic cells; Synthesis of receptor site specific chemicals derived from animo acids and nucleodises; Develop binding assays for identification of specific binding fractions; Develop insoluble support materials with covalently-linked specific substrates for affinity chromatography; Solubilize and fractionate the plasma membrane to isolate fractions which bind specific substrates; Use receptor-site specific probes to label and follow the isolation of specific fractions of membrane and to study the inhibitory properties of the probes in the intact cell; and develop membrane from intact cells and isolate membranes in which to study transport and to correlate with transport activity in intact cells.